Tumor necrosis factor-alpha polymorphism in Brazilians with different periodontal conditions

Objective: The aim of this study was to determine the frequency of the TNF-alpha (-308) genetic polymorphism in subjects with different periodontal conditions from a Brazilian population. Methods: One hundred and fifty-four subjects categorized as periodontal health (PH = 33; mean age = 29.4 ± 11.2 years), gingivitis (G = 21; mean age = 32.6 ± 11.4), chronic (CP = 64; mean age = 47.4 ± 12.4) and aggressive (AP = 36; mean age = 32.5 ± 11.1) periodontitis participated in the study. Periodontal clinical measurements were recorded at 6 sites/tooth in each subject. Mouthwash samples were collected for human DNA isolation. Detection of the polymorphism was carried out by polymerase chain reaction and restriction enzyme digestion. Differences in clinical parameters and frequency of genotypes among groups were sought by Kruskal-Wallis and X² tests. Results: Patients within the CP (PPD= 2.7 ± 0.1; CAL = 3.6 ± 0.2) and AP (PPD = 3.3 ± 0.1; CAL = 3.9 ± 0.2) groups presented significantly more periodontal destruction and inflammation (p < 0.001) than individuals in the PH (PPD = 1.7 ± 0.05; CAL = 1.7 ± 0.07) and G groups (PPD = 2 ± 0.05; CAL = 2 ± 0.07). The allele -308G was detected in 95% of all subjects, whereas the -308A allele was significantly more frequent in individuals of the PH and G groups (X² = 14.3; p < 0.05). The prevalence of the GG genotype was significantly higher in patients with chronic (63.2%) and aggressive periodontitis (46.2%), while the AA genotype was detected only in subjects with periodontal health (9.5%) and/or gingivitis (22.2%) (X² = 17.6; p < 0.01). Conclusion: These data suggest that the -308A allele and/or AA genotype may be associated with less periodontal destruction in this particular Brazilian population. Supported by CNPq,FAPERJ,Brazil.